Full range fuel mixer



May 25, 1943. A. G. B ODINE, JR

I FULL RANGE FUEL MIXER Filed Sept. 26, 1941 3 Sheets-Sheet 1 Zhwentor: ALBERT G. Boo/0'5;-

(Ittomeg.

May 1943- t A. G. BODINE, JR 2,319,971

FULL RANGE FUEL MIXER Filed Sept. 26, 1941 3 Sheets-Sheet 5 3nventor;

Gttpmeg ,pression it is in Patented May 25, 943

Albert G. Bodine, Jr.,

Burbank, Calif., assignor to American Liquid Gas Corporation, Los Angeles,

of California I 26, 1941, Serial. No. 412,420

Calif., a corporation Application September 3 3 Claims.

This invention relates to the carburetlon of fuel for internal combustion engines, and particularly pertains to a full range fuel mixer.

In the operation of internal combustion engines in which a product known as liquid gas is used as the engine fuel, various problems arise which are not present in connection with the use of gasoline 'and the like as a fuel. Liquid gas, which represents the propane-butane'fractions of the hydrocarbon series, is characterized by the fact that when the fluid is under comliquid phase, and that when it in vapor phase. It is therefore in temperature of the engine equipment will make variation in the character and phase of the fuel. It is therefore necessary to provide fuel control and carburetion means which will insure proper mixture of the fuel when the engine is cold and is to be started, and a different mixture after the engine has reached its normal operating temperature. Such devices require the use of a fuel mixer which will act automatically to produce a rich fuel when the engine is started and a lean fuel when theengine is operating under normal conditions, and which device will also provide auxiliary enrichment of the fuel during full throttle or periods of heavy load demand upon the engine. It is the principal object of the present invention, therefore, to provide a fuel mixer for gaseous hydrocarbons, which will act automatically to supply the engine with a properly constituted fuel 'der all periods of engine operation.

is released it is evident that variation vision of a converter through which high pressure fuel is reduced in pressure and delivered to ajrnixer, the mixer being controlled by a throttle acting automatically tomaintain the fuel at a desired degree of enriv hment throughout the tire range of engine operation. 1 The invention is illustrated by way of example the accompanying drawings in which: Figure 1 is a view in side elevation disclosing the application of the present invention to an internal combustion engine.

Fig. 2 is an-enlarged view in vertical section and elevation showing the fuel mixer.

Fig. 3 is a view in transverse section through the fuel mixeras seen on the line 3-3 of Fig. 2. Fig. 4 is a view in vertical section showing a form of the invention in which gas feed volume is regulated by engine suction to establish and eliminate a priming action.

Fig. 5 is a view similar to that shown 'in'Flg. 4

disclosing an automatic-valve arrangement to The present invention contemplates the pro initiate and interrupt a high pressure priming action under conditions of high engine suction.

.Referring more particularly to the drawings, It indicates an internal combustion engine within'which fuel'is to be ignited for the production of power. Mounted in advance of the engine is a radiator II. This is connected with the engine jacket through a conduit l2 which at its upper end is secured to a fitting l3 and at its lower end connects to a thermostat ll. Mounted upon the block of the engine cylinder is an exhaust mamfold l5 suitablyattached to an exhaust pipe l6 and an intake manifold IT. The intake manifold I1 is formed with a central distributing chamber l8 having an opening in its upper horizontal wall. Fitted over this opening is a gas mixer generally indicated at is and with which the present invention is particularly concerned.

Referring more particularly to Figs. 2 and 3 of the drawing, it will be seen that the gas mixer includes a-lower fitting 20 and a body structure 2 I The lower fitting 20 is formed with a bolting flange 22 which fits against the upper wall of the manifold chamber l8 andis secured in place by screws 23. A central throat 24 extends upwardly through the fitting 20. and is formed at its upper end with an outwardly flaring wall portion '25.

The body structure 2| is here shown as formed integral with the fitting 20 and is formed with an upwardly extending cylindrical portion 26 having a central bore 21 of a-diameter greater than the bore of the throat 24, shoulder 28 upon which a Venturi throat sleeve 29 is disposed. This sleeve has an upwardly and inwardly flaring throat wall 30 terminating adjacent to the center of the'sleeve and an upwardly and outwardly flaring'wall 3|. The outer circumference of the sleeve is formed with an annular groove 32 of substantially triangular shape. A plurality of jet openings 33 are formed through the wall inthe approximate plane of the apex of the groove 32. Extending laterally from the cylindrical portion having a central opening 35 therein which establishes communication between a fuel supply and the V-shaped groove 32, thus permitting the inflow of fuel to the groove 32 so that the fuel may be drawn in through the jet openings 33 to the restricted portion of the Venturi throat.

Asshown in Fig. 3 of the drawin s, an economizer unit 35 is formed on the side of the member 34. This unit includes a cup-shaped base 31 having a central cylindrical cavity 38. Disposed in the cavity is a flexible diaphragm 39 at the center of which is a diaphragm disc 40. Mounted thus forming a 26 is a tubular member 34- against the upon and extending through the diaphragm disc is a piston rod 4i which passes through an opening 42 in the wall of the member 34 and transversely of the passageway 35. Secured upon the end of the rod- 4| is a piston 43 which reciprocates in a cylindrical bore 44 in the wall of the extension 34. The diameter of the piston- 43 and the bore 35 in the extension 34 are substantially the same, so that as the piston moves across the bore it tends to close the same. The diaphragm 39 is secured in position by a cover 45 which has a flange portion resting against the margin of the diaphragm 39 and cooperates with the cup 31 to hold the diaphragm when screws 46 are tightened. A cavity 41 is formed in the cover 45 above the diaphragm. This cavity is substantially frusto-conical in shape and at its apex is formed with a central opening 48 receiving an adjusting screw 59. An opening 48 is formed through the wall of the cover 45 and connects with the opening 48. The screw 58 carries a washer 50' at its lower end which regulates the effective opening.

to the cap 45 from a vacuum connection nipple A tube 52 connects with this nipple and in turn is connected with a nipple 53. The nipple 53 is in direct connection with the throat 24 of the member 20 through passageway 54.

Extending from the passageway 35 of the extension 34 is an idling passageway 54 which communicates with the passageway 35 at a point between the position of the piston 43 and the annular space 32. The idling passageway 54 extends downwardly and communicates with the throat 24 at a point adjacent to the manifold.

An adjusting screw 55 is provided to enter the idling passageway 54 and to regulate the flow of fiuid therethrough. Extending transversely of the passageway 35 in the tubular extension 34 is a main jet adjusting screw 56 which may be adjusted to move across the opening and vary the effective area of the passageway 38. A coil spring 51 is disposed around the shank of the screw 58 and frictionally holds it against accidental rotation,

which a cylindrical bore 59 is formed. The cylindrical bore 59 has a longitudinal center line extending at right angles to the longitudinal center line of the passageway 24. The inner end of this bore is provided with an end wall having a central passageway 69 to receive a bushing 6!.

The bushing 6| is provided as a guide for a jet pin 62 which at its inner end projects beyond the end ofthe bushing for a purpose to be hereinafter described. The outer end of the pin is formed with an enlarged head which extends into a guide bushing 63 which is mounted within the end of the cylindrical bore 59. Yieldably held head of the pin is the point of a valve element 64. This valve element has a frustoconical body portion which seats against a valve seat 65 held by a threaded nut 83. A spring 6I rests against the base of the valve element 64 and urges the valve element onto its seat. The

outer end of the spring is held in position by a threaded plug 68 by which the outer end of the cylindrical bore 59 is sealed. Extending laterally from the cylindrical bore 59 is a passageway 69 which receives the threaded end of an L pipe fitting I8. The opposite threaded end of the pipe fitting is provided with a coupling nut II to which a tubular conduit I2 is connected. The conduit I2 leads to an orifice control valve I3 and then to a pipe I4. One side of the pipe is connected with a coil I5 which in turn passes through a reducing valve I6, which lowersthe gas pressure to atmospheric pressure, and then leads through a pipe 11 to the tubular extension 34 of the mixer housing.

A fuel supply tank I8 is fitted with a pipe I9 which leads to a coil 88. Interposed between the coil and the coil I5 is a reducing valve 8|. This reduces the pressure of the gaseous fuel from a relatively high pressure, such for example as 150 pounds to a pressure of the order of 15 pounds gauge pressure. 'I'he coils I5 and 80 are included in suitable shells 82 and 83, respectively, through which water is circulated in series with the water circulating system of the radiator ll, conduits 84 and 85 being provided for this purpose.

From the foregoing it will be seen that the pipe 17 will conduct the gaseous fuel to the mixer i9 at substantially atmospheric pressure and that the pipe I2 will conduct gaseous fuel to the opposite side of the mixer at a. higher pressure, such for example as 15 pounds gauge pressure.

butterfly valve is disposed with relation to the end of the jet pin 62 so that as the valve swings to a full open position the jet pin will be engaged and will move to lift the valve element 64 from its seat 65 to permit an additional amount of high pressure gas into the throat 24.

In operation of the present invention fuel is supplied from the tank I8. As previously described, this fuel is preferably known as liquid gas, which has the characteristic of being in liquid phase under pressure and in vapor phase when released. It will be assumed that the pressure of the gas within the tank I8 is of the order of pounds. This fuel is conducted through the pipe I9 to the coil 80 of a heat exchanger and then passes through a reduction valve 8|, at which time the pressure of the gas is reduced. In the present instance it will be assumed to be reduced to 15 pounds pressure. Fuel at reduced pressure is then conducted through a pipe I4 and may pass into a pipe I2 or a heat exchange coil I5. The shells 82 and 83 of the heat exchanger coils I5 and 88, respectively, are inthe circulation stream of the radiator II. This provides a suitable temperature control for the gaseous fuel as well as the cooling water of the engine II.

The fuel which passes from the coilI5 enters the line 11. At a point intermediate the length of the line 11 a reduction valve I8 lowers the pressure of the fuel to atmospheric pressure. It is to be understood that the pressures referred to by way of example in this case are gauge pressures and not absolute pressures. In the line 01' the tube I2 an orifice control valve I3 is provided. This controls the flow of the high pressure stream of fuel to the pipe I2 and to the jet cylinder 59. Normally, flow of the high pressure fuel from the jet cylinder 89 is prevented by the jet valve 84. The fuel which flows through the tube 11 to the fuel inlet passageway 35 of the extension 34 is regulated in its fiow through the passageway 35 by adjustment of the main jet adjusting screw 58 which is set across the throat of the passageway 35 and determines the effecwith a proper supply rupt the jet cylinder 59, since the spring 51 will force tive area through which the low pressure fuel may pass.

The present invention is particularly concerned of gaseous fuel when the engine is initially started or when the engine is laboring under a heavy load. It will beassumed that before starting the butterfly throttle valve 86 is standing at a position partially closing the inlet throat 24 of the mixing structure 19. When the engine is started the throttle is forced wide open. This causes a swinging end of the butterfly valve 86 to engage the end of the-jet pin 62' and force this pin outwardly in its bushing 6| while moving the jet valve element 64 from its seat 65. When this takes place an additional charge of fuel gas will enter the throat 24 and will be drawn downwardly by the engine suction. This entering gas is at a pressure of 15 pounds gauge. It will be understood of course that the engine suction will act through the openings 33 to draw the relatively low pressure gaseous fuel from the pipe 11 and through the passageway 35 into the groove 32 around the Venturi throat sleeve 29. This incoming gas at atmospheric pressure will commingle with the high pressure gas flowing from the tube 12 and the air which is drawn downwardly from an air inlet hood 69 as fuel is drawn to the engine. When the engine has been properly started or after it has operated under an excessive load the butterfly valve 86 may be withdrawn slightly from its position of pressure against the end of the jet pin 62 and from its full throttle position. This will interflow of gas under high pressure from the the valve member 64 onto its seat. Engine performance may then be continued with the supply of gas delivered through the supply pipe 11 and through the passageway 35 to the openings33.

Under normal operating conditions it may be desirable to automatically restrict the effective area of the passageway 35. This takes place by the suction of the engine through the nipples 53 and and the intermediate tube 52. tion will act within I the chamber' 41 of the economizer unit 36 to draw the diaphragm 39 and the diaphragm piston 4| across the passageway 35 and at the same time draw the piston 43 to a partially obstructing position within the passageway 35. Attention is directed to the fact that when the engine is idling a direct flow of fuel takes places from the passageway 35 through the idling duct 54 and to the throat 24 of the mixer.

In the foregoing part of the specification the construction and operation of the form of invention shown in Figs. 13 have been made. In this form of the device the priming action is initiated positively by movement of the throttle to a predetermined position at which point a priming valve is opened. It is possible to produce a priming action automatically as created by suction. of the engine, and in Figs. 4 and of the drawings structures for accomplishing this result are disclosed.

Referring particularly to Fig. 4, it will be seen that the normal fuel supply passageway 35 is provided with a side duct 99. Mounted within this duct is a valve tube 9| which extends outwardly into a diaphragm chamber 92. A cover 93 closes the outer end of the diaphragm chamber 92 and holds a flexible diaphragm 94 in position across the end of the diaphragm chamber 92. An air duct 95 is formed in the cover 93 and thus provides atmospheric pressure on the outer invention it will be noted face of the'diaphragm 94. A spring 96 is disposed around the valve tube 9| and acts to lift the diaphragm 94 from sealing contact with the outer end of the valve tube 9|. A duct 91 establishes communication between the diaphragm chamber 92 and the main throat 24 of the carburetor. The point at which the duct 91 communicates with the throat 24 is between the position of the throttle valve 86 and the connection with the engine. In operation of this form of the that under starting conditions or heavy load engine performance at low engine suction the spring 96 will act upon the diaphragm 94 to hold the diaphragm out of contact with the end of the valve tube 9| and will thus allow gaseous fuel to be drawn from the fuel passageway through the duct 99 to the diaphragm chamber 92 and to the duct 91. Thus, at this time fuel will be delivered tothe mixer through the main fuel passageway 35 to the Venturi throat and directly into the fuel mixture through the duct 91. When, however, the engine suction increases to the extent of overcoming the expansive action of the spring 96 the diaphragm 94 will be drawn against the end of the tube.9l and will interrupt the introduction of fuel directly into the mixture through the duct 91. Thus, at low engine vacuum this arrangement will act to prime the gaseous mixture with fuel, and at high engine vacuum thus conserving the consumption of fuel at high speed and low load conditions.

In the form of the invention shown in Fig. 5 of the drawings, the I fitted with the diaphragm 94, which is held in place by the cover 93. A valve tube 98 extends through an opening 99 in the cover andprojects against the outer side of the diaphragm 94. A diaphragm spring I is positioned within the diaphragm chamber 92 and forces the diaphragm to seat against the endface of the tube 98. This tube is connected with a conduit 12' similar to the conduit 12 described previously as conducting fuel at high pressure to the mixer. The diaphragm chamber 92 is connected with the throat of the mixer 24 through the duct 91 as described with reference to Fig. 4 of the drawings. In the operation of this structure, however, the throttle valve 66 must be moved toward a closed position in order to create sufficient suction to overcome the expansion of the spring I90 and to permit the high pressure gas into the stream of gaseous fuel passing through the mixer to the engine. This will act to prime the engine with rich gas delivered under high pressure.

It will thus be seen that here shown with a gaseous pressure a suitable supply of fuel may be delivered to the engine at all times, conditions when the fuel should normally required the structure may be instantly operated to introduce an auxiliary supply of gas at high pressure to the normal fuel supply, and to thereafter adjust itself to operating conditions and reduce the richness of the fuel as the engine reaches normal working speed.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of my invention as claimed.

by use of the mixer will interrupt this priming action,

diaphragm chamber 92 is to flow from the .conduit 12' and to thus be introduced directly fuel under positive and that under be richer than Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A gaseous fuel mixer, comprising a housing having a passageway therethrough connected at one end to the intake of an internal combustion engine, the opposite end being in communication with the atmosphere, means for introducing a normal charge of gaseous fuel into the flow of air drawn through said passageway to the engine, means for introducing an auxiliary supply of gaseous fuel into said air stream at higher pressure than that of the normal supply, a valve normally interrupting the flow of said auxiliary supply, a throttle valve for controlling the flow of fluid in the air stream, and operating means associated with the valve of the auxiliary fuel supply, whereby when the throttle valve reaches a full open position the auxiliary valve will be opened.

2. A gaseous fuel mixer, comprising a mixer housing, an air passageway centrally thereof and connected with an engine intake at its lower end, a ,Venturi throat structure formed within said passageway and through which the air flows, a throttle valve disposed in said flow stream between the Venturi throat and the engine, whereby the flow of fluid from the Venturi throat to the engine maybe metered, means for introducing a stream of gaseous fuel into said Venturi throat to mix with the air being drawn therethrough and to form a carbureted fuel, means for introducing an auxiliary supply of gaseous fuel into the stream of carbureted fuel passing to the engine, a gaseous fuel supply, means delivering said fuel to the normal fuel supply means at one pressure, means for delivering fuel to the auxiliary supply means at a higher pressure, a valve normally preventing the inflow of the high pressure fluid to the carbureted fluid stream, and cooperating means between the throttle valve and said auxiliary fuel valve, whereby the auxiliary fuel valve will be opened only when the throttle valve is in a'predetermined position.

' 3. The structure of claim 2 including an economizer structure disposed within the path of inflow of the normal gas supply and acting under engine suction to vary the effective area of the passageway for said gas supply.

ALBERT G. BODINE, JR. 

